1. Bussy, Journ. de Pharm. 19, 1 (1833).
2. Tromsdorff, Tromsdorffs neues Journ. d. Pharmazie 24, 95 (1832).
3. Bley, Tbomsdorffs neues Journ. d. Pharmazie 24, 95 (1832).
4. Christophsohn, Diss. Dorpat 1874.
5. F. A. Flückiger, Arch. d. Pharm. III. Reihe 10, 532 (1877).